Mechanical stub tuner



March 1, 1966 w R T, JR

MECHANICAL STUB TUNER Filed March 25, 1964 Lloyd W. Root Jr.

mmvrog.

United States Patent QMECHANICAL STUB TUNER I Lloyd W. Rodt, Jr., Huntsville, Ala., as'signor to the United States of America as represented by the Secretary of the Army Filed Mar. 25, 1964, Ser. No. 354,806 6 Claims. (Cl. 333-98) (Granted under Title 35, US. Code (1952), sec. 266) This invention may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

My invention relates to a mechanical stub tuner in which mechanical means are provided by adjusting the stub tuner and in which the mechanical means is so designed as to enable use of the stub tuner without the detrimental effect of body capacitance.

In stub tuners in which the adjustment thereof is effected by body capacitance, a need has arisen for an adjusting means by which the stub tuner can be accurately and finely adjusted.

Therefore, it is an object of this invention to provide a mechanical means by which the stub tuner can be adjusted with substantially no body capacitance interference.

Another object of this invention is to provide a mechanical means by which the stub tuner may be actuated remotely.

Still another object of this invention is to provide a mechanical adjusting means for the stub tuner in which the adjusting means is mounted directly on the stub tuner.

A further object of this invention is to provide a mechanical actuating unit which is adapted to be directly connected to the branch and shorting stub plunger of the stub tuner.

Yet another object of this invention is to make the mechanical actuating unit of such a design as to capacitively isolate an operator from the stub tuner.

The need for an adjusting means by which the stub tuner may be finely adjusted, without interference due to body capacitance, has been satisfied by providing a mechanical adjusting unit of such a design as to substantially remove the operator from the stub tuner.

The single figure of the drawing is a plan view, with portions cut away and in section, of the mechanical stub tuner.

The invention may be better understood by reference to the drawing in which, numeral 1 designates a stub tuner. The stub tuner includes a base housing 3 which has a tubular branch 5 and a shorting stub plunger 7 mounted in tubular branch 5, for linear movement relative thereto. Shorting stub plunger 7 is moved relative to tubular branch 5 and to a conductor inside tubular branch 5 to adjust the tuning of the stub tuner. Helical shaped cap nut 6 and means therein are used to keep foreign debris out of tubular branch 5. Prior to the addition of unitary mechanical adjusting means 9, cap nut 6 and the means therein were used to clamp stub plunger 7 in place.

Unitary mechanical adjusting means 9 includes a U- shaped support member 11 which has parallel spaced bores 13, 15, 17. Bore 13 is of such a size as to receive tubular branch 5, and set screws 19 clamp U-shaped member 11 to tubular branch 5. Bore 15 slidably receives guide rod 21, and bore 17 is threaded at each end to receive threaded stem 23. Operating knob 25 rotatably connects threaded stem 23 to one end of connecting member 27. The other end of connecting member 27 is connected to shorting stub plunger 7 by bolt 29, and

3,238,473 Patented Mar. 1, 1966' guide rod 21 is integrally connected to connecting member 27 near the center thereof.

In operation, knob 25 is rotated clockwise or counter clockwise by an operator to adjust the shorting stub plunger 7 relative to branch 5, to adjust the tuning of the stub tuner 1. Guide rod 21 guides plunger 7 and lends support to connecting member 27.

Since aluminum and brass work well together, U- shaped support member 11 and knob 25 are made of aluminum, while guide rod 21, threaded stem 23 and connecting member 27 are made of brass. The design of the unitary adjusting means 9 is such that a human operator is capacitively isolated from the stub tuner when adjusting the stub tuner. That is, unitary adjusting means 9 holds shorting stub plunger 7 in the position to which it is adjusted and operating knob 25 is so remove-d from the stub tuner as to remove the operator away from the stub tuner to capacitively isolate the operator from the stub tuner. In some stub tuners, the mere contact of an operators hand with nut 6 causes the short circuit reading of the stub tuner to vary, and this is objectionable. This variation in the short circuit reading is apparently caused by body capacitance. With this capacitively isolating type design of the unitary mechanical adjusting means, the stub tuner can be more accurately and more finely tuned. It is also pointed out that materials other than brass and aluminium may be used, and such other materials may be for example, nylon, Teflon, etc.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

I claim:

1. The combination comprising: a stub tuner including a base and a branch on the side thereof, a shorting stub plunger mounted in said branch and mounted for linear adjustment relative to said branch; and unitary mechanical adjusting means mounted on said branch and connected to said shorting stub plunger for adjusting said shorting stub plunger relative to said branch, said unitary mechanical adjusting means including, a support member mounted on said branch, an actuator screw threadedly mounted in a threaded bore of said support member, and said connecting means including a substantially flat member connecting said shorting stub plunger to said actuator screw to impart linear movement of said actuator screw to said shorting stub plunger.

2. The combination as set forth in claim 1, said unitary mechanical adjusting means further including a guide, said guide being slidably mounted relative to said support member and integrally connected to said fiat member.

3. The combination as set forth in claim 2, wherein said support member is made from aluminum, and said substantially flat member, said actuator screw and said guide are made from brass.

4. A mechanical stub tuner including: a tuner housing including a base and at least one tubular branch projecting therefrom, a shorting stub plunger mounted in said tubular branch for adjustment relative thereto; and mechanical adjusting means for adjusting said shorting stub plunger relative to said tubular branch, said mechanical adjusting means being mounted on said tubular branch and connected to said shorting stub plunger, said mechanical adjusting means being made of such design as to capacitively isolate an operator from the tuner housing and stub plunger, and including, a U-shaped member having a base and two side arms, said arms having two parallel bores therethrough, one of said two parallel bores receiving said tubular branch, and set screws J in said arms for clamping said arms to said tubular branch, a threaded bore through said base and parallel to said two parallel bores, a threaded stem threaded into said threaded bore, a guide rod slidably mounted in the other of said two parallel bores, a connecting member connected to said shorting stub plunger and projecting therefrom, an operating knob rotatably connecting said threaded stem to said projecting portion of said connecting member, and means connecting said guide rod to said .connecting member, whereby when said operating knob is rotated, said shorting stub plunger is caused to slide relative to said tubular branch.

5. A mechanical stub tuner as set forth in claim 4, wherein said U-shaped member and said operating knob are made of aluminum, and said threaded stem, said guide and said connecting member are made of brass.

6. A unitary mechanical adjusting means, for adjusting a stub tuner, comprising; a support member, said support member including three parallel bores, a first one of said bores adapted to receive a branch of a stub tuner and to be clamped thereto, a second one of said bores receiving a guide rod, a third one of said bores being threaded and receiving a threaded stem, a connecting member integrally connected near the center thereof to said guide rod, a knob rotatably connecting one end of said connecting member to said threaded stem, and another end of said connecting member being adapted to be connected to a plunger of a stub tuner, whereby when the stem is rotated by said knob, said connecting member is caused to move relative to said support member.

References Cited by the Examiner UNITED STATES PATENTS 2,819,453 1/1958 Cohn 333-83 2,853,678 9/1958 Tomiyasu 333-83 2,950,453 8/1960 Kline et al. 333-83 ELI LIEBERMAN, Acting Primary Examiner.

L. ALLAHUT, Assistant Examiner. 

1. THE COMBINATION COMPRISING: A STUB TUNER INCLUDING A BASE AND A BRANCH ON THE SIDE THEREOF, A SHORTING STUB PLUNGER MOUNTED IN SAID BRANCH AND MOUNTED FOR LINEAR ADJUSTMENT RELATIVE TO SAID BRANCH; A UNITARY MECHANICAL ADJUSTING MEANS MOUNTED ON SAID BRANCH AND CONNECTED TO SAID SHORTING STUB PLUNGER FOR ADJUSTING SAID SHORTING STUB PLUNGER RELATIVE TO SAID BRANCH, SAID UNITARY MECHANICAL ADJUSTING MEANS INCLUDING, A SUPPORT MEMBER MOUNTED ON SAID BRANCH, AN ACTUATOR SCREW THREADEDLYY MOUNTED IN A THREADED BORE OF SAID SUPPORT MEMBER, AND SAID CONNECTING MEANS INCLUDING A SUBSTANTIALLY FLAT MEMBER CONNECTING SAID SHORTING STUB PLUNGER TO SAID ACTUATOR SCREW TO IMPART LINEAR MOVEMENT OF SAID ACTUATOR SCREW TO SAID SHORTING STUB PLUNGER. 